Anti-lock brake system for a bicycle

ABSTRACT

An anti-lock brake system for a bicycle having sliding assembly (having a brake shoe therein) and a plurality of springs defined in a brake shoe holder in turn, a bottom of the brake shoe holder and a connecting side of the sliding assembly are correspondingly in gradient formed and both of them to be abutted against each other and they are slanted formed outwardly in accordance with the direction of the rotation of the tire of the bicycle. The sliding assembly further includes a plurality of recesses formed therein for receiving sliding members, an abrasion-resistant member disposed at the bottom of the recess of the brake shoe holder.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a brake device, and moreparticularly to an anti-lock brake system for a bicycle.

[0003] 2. Description of the Prior Arts

[0004] A conventional brake device for a bicycle generally includes apair of brake shoes and a mounting bracket, the brake shoes are coupledto both legs of the mounting bracket and then the mounting bracket ismounted to the rear and/or front fork of a bicycle with the brake shoesstanding oppositely at both sides of the wheel rim of the bicycle. Thebrake shoes are employed to press against the wheel rim from both sidesby virtue of the mounting bracket and a friction to be generated to stopthe rotation of the tires. This kind of brake device has been commonlyused in nowadays, however, there are still some shortcomings need to beimproved:

[0005] In event of an emergency brake, the braking force is greater thanthe friction force of the tires due to a great force applied by therider to press on the hand brake in order to stop the rotation of thetires, which will generate a dead lock of the tire in a sudden andresult in a skidding and overturning of the bicycle and hurt of therider.

[0006] A buffering device targeting at the solution of the above problemis shown in FIG. 1 including: a brake shoe holder 10, the brake shoeholder 10 to be mounted to a brake mounting bracket by virtue of aconnecting rod 11 coupled at a side opposite to the wheel rim of thetire and has a pair of protruding edges opposite to each other defininga space for accommodating a sliding piece 17 therein, furthermore, thebrake shoe holder 10 defining a threaded hole 12 at a first end forengaging a bolt 13 and a recess 14 at a second end for accommodating anelastic member 15, a brake shoe 16 to be engaged in the sliding piece 17and the sliding piece 17 has a first end connected to the elastic member15 and a slot 18 defined at a second end engaging with the bolt 13 forpreventing the sliding piece 17 from sliding out from the brake shoeholder 10, in such a manner, taking use of the slide of the slidingpiece 17 in the space of the brake shoe holder 10 and the elastic member15 to buffer a friction of the brake shoe 16 while it pressing againstthe wheel rim the tire. Although this braking device has been commonlyused, there are also some shortcomings need to be improved:

[0007] First, this braking device is too complicated that the brake shoeholder 10 not only needs a pair of protruding opposite edges to define aspace for the receiving and slide of the brake shoe 16 therein but alsothe brake shoe 16 should be engaged in the a sliding piece 17 having aslot 18 for engaging a bolt 13, in this case, it's not only complicatedin assembling process but the production cost is increased as well.

[0008] Second, there is only a very short distance (about a 1 mm indistance) for the slide of the brake shoe 16 in the brake shoe holder 10according to this device, which is not long enough for buffering thefriction generated from the braking motion and accordingly a rider isnot able to control the bicycle effectively.

[0009] Third, in accordance with the brake device for a bicycle, thebrake shoe only has a very short contracting distance while a brakingmotion being operated and it will be contracted to an end thereof andwill not return to the original position till the rider release thehandle brake, thereby, there will be a great friction caused from a partof the tire and the ground and do a great harm to the tire.

[0010] Fourth, in accordance with this conventional brake device for abicycle, the brake shoe holder 10, the recess 14, the brake shoe 16 andthe sliding piece 17 all move in a straight line, however, the tires ofthe bicycle do rotational movement, in such a manner, a stress of thetire is generated from the friction of the brake shoe 16 while a brakingmotion being operated which can't be transmitted completely to theelastic member 15 and a part of it can't be counteracted (which isperpendicular to a direction of the movement of the brake shoe 16), as aresult, the brake shoes 16 is not allowed to move smoothly and freely inthe space of the brake shoe holder 10 and great frictions and collisionswill be caused in the related parts.

[0011] The present invention has arisen to mitigate and/or obviate theafore-described disadvantages of the conventional anti-lock brake systemfor a bicycle.

SUMMARY OF THE INVENTION

[0012] In accordance with one aspect of the present invention, there isprovided an anti-lock brake system for a bicycle having sliding assembly(having a brake shoe therein) and a plurality of springs defined in abrake shoe holder in turn, an acting direction and location of thesprings are corresponding to that stress direction of the brake shoe,the brake shoe is partially engaged in the brake shoe holder, a bottomof the brake shoe holder and a connecting side of the sliding assemblyis correspondingly in gradient formed and both of them to be abuttedagainst each other and slantingly formed outwardly in accordance withthe direction of the rotation of the tires of the bicycle.(For analternative that a plurality of sliding members also can be definedbetween the bottom of the brake shoe holder and the sliding assembly andin addition, an abrasion-resistant member can be defined at the bottomof the recess of the brake shoe holder). In such a manner, which notonly can buffer a braking friction generated from an emergency brake butalso prevent a great friction from being caused in the related parts ofthe braking device.

[0013] The primary objective of the present invention is to provide animproved anti-lock brake system for a bicycle, which is not only capableof buffering a braking friction from being generated from an emergencybrake but also preventing a great friction caused in the related partsof the braking device.

[0014] Another objective of the present invention is to provide a simpleanti-lock brake system for a bicycle, which is not only reduce theproduction cost to the least but also simplify the assembling process.

[0015] A further objective of the prevent invention is to provide animproved anti-lock brake system for a bicycle allowing a free and smoothslide of the sliding assembly in the brake shoe holder and the quickreturn of the brake shoe to the original position so as to provide asmooth braking operation.

[0016] The present invention will become more obvious from the followingdescription when taken in connection with the accompanying drawings,which shows, for purpose of illustrations only, the preferredembodiments in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1 is a cross sectional view of a conventional brake devicefor a bicycle;

[0018]FIG. 2 is an exploded view of an anti-lock brake system for abicycle in accordance with a first embodiment of the present invention;

[0019]FIG. 3 is an elevational view of an anti-lock brake system for abicycle in accordance with the first embodiment of the presentinvention;

[0020]FIG. 4 is a schematic illustration view in accordance with thefirst embodiment of the present invention showing an anti-lock brakesystem mounted to a mounting bracket of a bicycle;

[0021]FIG. 5 is a cross sectional view in accordance with the firstembodiment of the present invention of showing the status of ananti-lock brake system for a bicycle before a braking action beingoperated;

[0022]FIG. 6 is a cross sectional view in accordance with the firstembodiment of the present invention of showing the very beginning statusof an anti-lock brake system for a bicycle while a braking action beingoperated;

[0023]FIG. 7 a cross sectional view in accordance with the firstembodiment of the present invention of showing a continuous brakingaction of an anti-lock brake system for a bicycle is being operated;

[0024]FIG. 8 is a cross sectional view in accordance with the firstembodiment of the present invention of showing a second circle ofbraking operation of an anti-lock brake system for a bicycle;

[0025]FIG. 9 is an exploded view of an anti-lock brake system for abicycle in accordance with a second embodiment of the present invention;

[0026]FIG. 10 is a longitudinal sectional view of anti-lock brake systemfor a bicycle in accordance with the second embodiment of the presentinvention;

[0027]FIG. 11 is a cross sectional view in accordance with the secondembodiment of the present invention of showing the status of ananti-lock brake system for a bicycle before a braking action beingoperated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Referring to the FIGS. 2-4, in which, an anti-lock brake systemin accordance with one aspect of the present invention comprises a brakeshoe holder 20, a sliding assembly 30, a brake shoe 40 and two springs50. The brake shoe holder 20 has a shape of curved recess 21 and anopening 24 defined at a side facing to a wheel rim 60 and has bolt 22located at a bottom thereof which is respectively to be coupled to bothends of a mounting bracket 61 by virtue of the bolt 22 and screw nuts23. Both sides of the opening 24 are curvely formed with edges 25, agradient face 26 is slantingly formed outwardly in accordance with thedirection of the rotation of the tire of the bicycle at the bottom ofthe recess 21, two protrusions 27 are formed at a side corresponding tothe gradient face 26. The brake shoe holder 20 is curvely formed in anarc A corresponding to a rotary angel of the wheel rim 60.

[0029] The sliding assembly 30 is received in the recess 21 of the brakeshoe holder 20 and confined in the opening 24 by the curved edge 25. Thebrake shoe 40 is partially accommodated in sliding assembly 30 andpartially protruding the opening 24 of the brake shoe holder 20therefrom (corresponding to the both sides of the wheel rim 60 of thebicycle). A pair of protrusions 31 are formed at a side of the slidingassembly 30 corresponding to that protrusions 27 of the brake shoeholder 20. The sliding assembly 30 also has a gradient face 32slantingly formed outwardly in accordance with the direction of therotation of the tire of the bicycle at the bottom thereof which is incorresponding to the gradient face 26 of the brake shoe holder 20.

[0030] The spring 50 is accommodated in the recess 21 of the brake shoeholder 20 having a first end engaged with the protrusions 27 and asecond end engaged with the protrusions 31 of the sliding assembly 30.

[0031] Referring further to the FIGS. 5-8, which shows the firstembodiment of the present invention. In the FIG. 5 shows the status ofthe anti-lock brake system of the present invention before a brakingaction being operated, in which, the brake shoe holders 20 at both endsof the mounting bracket 61 are apart from the wheel rim 60 of thebicycle by virtue of the mounting bracket 61, the sliding members 30 arepushed to one end of the recesses 21 of the brake shoe holders 20 by thesprings 50 and further by the cooperation of the gradient face 32 of thesliding assembly 30 and the gradient face 26 of the brake shoe holder 20abutting against each other, thereby the wheel rim 60 of the bicycle isnot in the braking status( is not being pressed by the brake shoes 40).

[0032] Referring the FIG. 6, which shows the very beginning status of abraking action just be operated, when a rider press the hand brake, thebrake mounting bracket 61 will enforce the two brake shoe holders 20 topress against the wheel rim 60 of the bicycle and the part of the brakeshoe 40 protruding from the opening 24 of the brake shoe holder 20 beginto rub the wheel rim 60 of the bicycle, right this moment, a greatinertial stress will be transmitted to the brake shoes 40 from the wheelrim 60 of the bicycle, accordingly it will be further transmitted to thegradient faces 32 and the springs 50 by the brake shoes 40 and thesliding assembly 30, due to the inertial force of the bicycle is minorthan the elastic force of the springs 50, the sliding assembly 30 staymotionlessly in the brake shoe holders 20, and thereby the bicycle in alow speed can be stopped.

[0033] Referring to the FIG. 7, which shows a continuous braking action(an emergency brake) of an anti-lock brake system for a bicycle is beingoperated, in this status, both a force the rider pressed on the handbrake and the inertial force of the bicycle are very great, and theinertial force of the bicycle is greater than the elastic force of thesprings 50, so the sliding assembly 30 begin to push and compress thesprings 50, accordingly the sliding assembly 30 slide relatively in therecess 21 of the brake shoe holder 20 and slide slantingly outward by acooperation of the gradient face 32 of the sliding assembly 30 and thegradient face 26 of the brake shoe holder 20 abutting against each otherand the brake shoes 40 slide slantingly outward too, in such a manner, astress generated form the braking action can be absorbed by the gradientface 26 and the springs 50 without difficulties by virtue of the arc Aof the brake shoe holders 20, the sliding members 30 and the brake shoes40, thereby the friction force of the brake shoes will be reduced andthe braking force will not be greater than the friction of the tire ofthe bicycle (no dead lock of tire's rotation happened), furthermore, thewheel rim 60 can be a bit rotate forward and no overly great frictionforce between the tires and the ground caused and the rider will notlose steering.

[0034] Referring the FIG. 8, which shows a secondary circle of thebraking action, due to the slant slide of the brake shoes 40, thefriction force is reduced, the springs 50 begin to release the restoringforce pushing the sliding assembly 30 to return slantingly inward by thecooperation of the gradient face 26,32, which increase the frictionforce of the brake shoes 40 acting on the wheel rim 60, such an actionof the sliding members 30 will be repeatedly so as to achieve an effectof an anti-lock brake system and an emergency brake of the bicycle canbe smoothly eased off by the release and compress of the brakealternatively happened in a twinkling, in this manner the rider will notlose steering control of the bicycle and no overly friction caused inthe related parts.

[0035] Furthermore, the braking distance of the tire is based on theelastic force of the springs, the inclination of the gradient face andthe inertia force, so which can be adjusted by the manufacturers asdeferent requirements of the riders.

[0036] It is to be noted that the brake shoe holders 20 are permitted tobe whole-set replaced, which is easy for assembling and dismantling andthe structure is simple (reduce the production cost).

[0037] Referring again to the FIG. 2, a plurality of draining holes 70can be defined in a side of the brake shoe holder 20 which allowing forthe drainage of the mud or greasy dirt therefrom and allow the riderinject grease or clean the inside therethrough.

[0038] An anti-lock brake system for a bicycle in accordance with thefirst embodiment of the present invention is described as above.

[0039] In accordance with a second embodiment of the present inventionthere is provided another anti-lock brake system for a bicycle as shownin FIGS. 9-11 which structural arrangement is basically identical withthat of the first embodiment, the only difference is: a plurality ofsliding members 80 and an abrasion-resistant member 90 are added,furthermore, the sliding assembly 30 is provided with a plurality ofcavities 33.

[0040] The sliding members 80 may be metal balls, rollers, needlerollers or the like, slidably received in the respective cavities 33 ofthe sliding assembly 30, which will be rolling in the event that thesliding assembly 30 is sliding so as to provide a smooth slide of thesliding assembly 30 in the recess 21 of the brake shoe holder 20.

[0041] The abrasion-resistant member 90, corresponding to the gradientface 26 at the bottom of the recess 21 of the brake shoe holder 20, ismade from abrasion-resistant material, which correspondingly providing arolling friction to the sliding members 80.

[0042] Due to the working principles of the two anti-brake lock systemsin according with the first and second embodiment of the presentinvention are identical, further remarks on this matter will seemsuperfluous.

[0043] While we have shown and described various embodiments inaccordance with the present invention, it should be clear to thoseskilled in the art that further embodiment may be made without departingfrom the scope of the present invention.

What is claimed is:
 1. An anti-lock brake system for a bicycleoppositely mounted to a brake mounting bracket comprising: a brake shoeholder, a sliding assembly, a brake shoe and a spring, wherein: thebrake shoe holder has a recess defined at a side facing toward the wheelrim of a bicycle and coupled to a end of the mounting bracket, agradient face is slantingly formed outwardly in accordance with thedirection of the rotation of the tire of the bicycle at the bottomthereof; the sliding assembly is received and confined in the recess ofthe brake shoe holder by virtue of the formed edge, a brake shoe isreceived in the sliding assembly, the brake shoe partially protrudes outof the brake shoe holder by mounted at a side of the wheel rim ofbicycle, a gradient face is slantingly formed outwardly at a bottom ofthe sliding assembly in accordance with the direction of the rotation ofthe tire of the bicycle and corresponding to the gradient face of thebrake shoe holder; the spring is accommodated in the recess of the brakeshoe holder having a first end abutting against the brake shoe holdersand a second end abutting against the sliding assembly.
 2. The anti-lockbrake system for a bicycle as claimed in claim 1, wherein the brake shoeholder, the sliding assembly and the brake shoe each have an arc-shapedcorresponding to the arc of the wheel rim.
 3. The anti-lock brake systemfor a bicycle as claimed in claim 1, wherein the brake shoe holderdefines a bolt at a bottom so as to couple with the brake mountingbracket.
 4. The anti-lock brake system for a bicycle as claimed in claim1, wherein the brake shoe holder defines a pair of protrusions at a sidecorresponding to the gradient face and the sliding assembly also definesa pair of protrusions at a side, the protrusions of the sliding assemblycorresponding to that of the brake shoe holder, the spring has a firstend mounted onto the protrusion of the sliding assembly and a second endmounted onto the protrusion of the brake shoe holder.
 5. The anti-lockbrake system for a bicycle as claimed in claim 1, wherein the brake shoeholder defines a plurality of draining holes for allowing the drainageof mud or greasy dirt or allowing a rider to inject grease and clean ittherethrough.
 6. The anti-lock brake system for a bicycle as claimed inclaim 1, said sliding assembly has a plurality of cavities formed at aside corresponding to the recess of the brake shoe holder.
 7. Theanti-lock brake system for a bicycle as claimed in claim 6, furthercomprising a plurality of sliding members received in the correspondingcavities of the sliding assembly for bearing the sliding assembly toslide within the recess.
 8. The anti-lock brake system for a bicycle asclaimed in claim 7, further comprising an abrasion-resistant memberdisposed at the bottom of the recess of the break shoe holder forproviding a rolling friction with respect to the sliding members.
 9. Theanti-lock brake system for a bicycle as claimed in claim 7, wherein thesliding members are balls.
 10. The anti-lock brake system for a bicycleas claimed in claim 7, wherein the sliding members are rollers.
 11. Theanti-lock brake system for a bicycle as claimed in claim 7, wherein thesliding members are needle rollers.